On 3rd December the carrier announced an order to purchase 50 new Airbus A321XLR aircraft, enabling the carrier to begin replacing and retiring its existing fleet of Boeing 757-200 aircraft and further meet the airline's operational needs by pairing the optimal aircraft with select transatlantic routes.

United expects to introduce the A321XLR into international service in 2024, will also allow United to explore serving additional destinations in Europe from its East Coast Newark/New York and Washington Dulles hubs.

United VP and chief commercial officer Andrew Nocella said "The new Airbus A321XLR aircraft is an ideal one-for-one replacement for the older, less-efficient aircraft currently operating between some of the most vital cities in our intercontinental network. In addition to strengthening our ability to fly more efficiently, the A321XLR's range capabilities open potential new destinations to further develop our route network and provide customers with more options to travel the globe."

According to United’s October 2019 investor update, the airline is already in the process of retiring its 757 fleet, as it has already retired three of that aircraft type since the beginning of the year with another 73 still in service.

Private Sky Director David Scully said "This Global 5000 addition to the AOC is an important & exciting step for us. The addition of this aircraft provides our customers with the ultimate long-range capability. It will be strategically located to serve customers in Eastern as well as Western Europe".